The present invention relates to web handling and processing, and more particularly relates to an apparatus and method for marking a web at a selected location along its length as the web is being coiled or wound on a core member.
In numerous industrial applications, sheet like materials such as paper, film, foil and the like are handled in the form of semi-continuous webs, which are often stored in coil form. It is sometimes desirable to mark such a web at one or more locations along its length.
For example, cigarette tipping paper is often handled in semi-continuous web form. In one process, a coil containing a web of tipping paper may be mounted on the payout stand of a paper perforating machine, and the leading end of the web may be threaded through the machine, past the perforating apparatus of the machine to a takeup coil mounted on the takeup stand of the machine. The perforating apparatus is then started and the paper is fed past it by unwinding the paper from the supply coil and winding it onto the takeup coil. However, those portions of the web which were originally leading and which were threaded downstream of the perforating apparatus before it was started will not be perforated. It is desirable to mark the web at a location corresponding to the point of demarcation between perforated and unperforated portions of the web so that such point of demarcation can be detected during subsequent processing operations to prevent feeding of unperforated tipping paper to the cigarette making operation.